Twinkle light set

ABSTRACT

A twinkle bulb light set includes, alternately from one end of the light set to an opposite end of the light set, at least one standard bulb socket configured and dimensioned to operatively receive a standard or steady-burning bulb and at least one non-standard bulb socket configured and dimensioned to operatively receive a non-standard twinkle bulb. The standard and non-standard bulb sockets are configured and dimensioned to operatively receive only standard and non-standard bulbs, respectively. Preferably the standard bulb socket is smaller than the non-standard bulb socket in at least one dimension such that the standard bulb socket cannot operatively receive a non-standard bulb, and the non-standard bulbs have at least one dimension greater than that of the standard bulbs, thereby to preclude operative receipt of a non-standard bulb in a standard bulb socket.

BACKGROUND OF THE INVENTION

The present invention relates to a twinkle light set, and moreparticularly to a twinkle light set which meets Underwriters Laboratory(UL) standards for safety.

UL Standard 588 distinguishes between the flasher bulb (LAMP, FLASHING)and the twinkle bulb (LAMP, INDIVIDUAL FLASHING) as follows:

-   -   5.16 LAMP, FLASHING—A series-or parallel-connected lamp that        automatically cycles on and off by means of a bimetallic strip        connected in series with the filament. For series-connected        strings, the flashing lamp causes all lamps connected in series        with it to flash. For parallel-connected strings, only the        flashing lamp is intended to flash.    -   5.17 LAMP, INDIVIDUAL-FLASHING—A series-connected lamp that        automatically cycles on and off by means of a bimetallic strip        connected in parallel with the filament. The cycling of the        bimetallic strip causes only the individual-flashing lamp to        flash by momentarily placing a short across the filament to turn        the lamp on and off.

As used herein, in both the specification and the claims, the followingterms have the following meanings:

-   -   A “flasher bulb” refers to a flashing lamp as defined in UL        Standard 588, par. 5.16 ( 17 ^(TH) Ed.).    -   A “twinkle bulb” refers to an individual-flashing lamp as        defined in UL Standard 588, par. 5.17 ( 17 ^(th) Ed.).    -   A “steady-burning lamp” refers to a lamp which lacks a        biometallic strip and is either on or off depending upon the        voltage supplied to the lamp.    -   A “standard bulb socket” refers to a conventional socket        configured and dimensioned to operatively receive a conventional        standard bulb,—whether it be a conventional flashing lamp, an        individual-flashing lamp or a steady-burning lamp—and to not        operatively receive a non-standard twinkle bulb according to the        present invention.    -   A “non-standard bulb socket” refers to a socket according to the        present invention configured and dimensioned to operatively        receive only a non-standard twinkle bulb according to the        present invention and not to operatively receive a conventional        bulb.    -   A “non-standard twinkle bulb” refers to a twinkle bulb according        to the present invention which is configured and dimensioned to        be operatively received only in a non-standard bulb socket        according to the present invention and not to be operatively        received in a standard bulb socket.

It is well-known to provide a flasher light set wherein a flusher bulbcontains a thermally sensitive element which opens and closes theelectrical illumination circuit through the bulb according to its “hot”or “cold” state. When the circuit containing the thermally sensitiveelement opens, there is no electricity supplied to any other bulb inseries electrical communication therewith, so that each suchseries-connected bulb is temporarily extinguished until the elementcools and the circuit again closes. Thus, use of even a single flasherbulb causes an entire light set or a section thereof in seriescommunication to have its bulbs flash on and off with the flasher bulb.The appearance of a light set in which all of the bulbs or a section ofthe bulbs flashes on and off in unison presents an aesthetic attractionto a viewer.

However, an even more appealing an aesthetic affect is produced by atwinkle light set. Instead of a flasher bulb, the tinkle light set usesa twinkle bulb. The twinkle bulb is similar to the flasher bulb in thata thermally sensitive element opens and closes the electricalillumination circuit which provides illumination of the bulb. However,whereas in the flasher light set no current passes through the bulb whenthe illumination circuit through the bulb is open, in the twinkle lightset, each twinkle bulb has in parallel with the illumination filament abypass or shorting circuit. The bypass circuit (when closed) presents alow resistance, whereas the illuminating circuit (when closed) presentsa high resistance. As the twinkle bulb is illuminated through theillumination circuit, it heats up the normally open switch in the bypasscircuit, thereby to close the switch and provide an alternative lowresistance path through which the current will preferentially flow. Thisin turn terminates substantially all of the current passing through thehigh resistance illumination circuit and leads to cooling of the bulb.After a predetermined amount of cooling, the switch in the bypasscircuit returns to its normally open state so that current must flowonce again through the illumination circuit.

One major difference between a twinkle light set and a flasher light setis that each twinkle bulb acts independently of the other twinkle orstandard bulbs in series therewith because the twinkle bulb alwayspasses current therethrough (whether through the illumination circuit orthrough the bypass circuit). Thus, in a twinkle light set, a widevariety of aesthetic affects may be obtained dependent upon theplacement of the twinkle bulbs. For example, a twinkle light set mayconsist of a plurality of substantially vertical light strings, witheach bulb in a given light string being in series. A set of lightstrings (at least one light string being in each light string set) maycontain only ordinary or standard steady-burning bulbs, while analternate set of light strings (at least one light string being in eachlight string set) may contain only twinkle bulbs. The standard bulbsremain on constantly, while the twinkle bulbs twinkle on and offindependently of each other, seemingly at random, as a counterpoint toprovide an enhanced aesthetic appearance. Clearly any given lightstring(s) may include both standard and non-standard twinkle bulbs forproviding a more startling aesthetic experience.

In a conventional twinkle light set typically a large or majorproportion of the bulbs (at least 50% thereof) are ordinary to standardsteady-burning bulbs. Thus, even if all of the illumination circuits ofall of the twinkle bulbs were, through happenstance, to open at the sametime, so that each of the twinkle bulbs presented only the lowresistance bypass path to the current, the standard bulbs (with theirhigh resistance illumination circuits) would dissipate the currentsufficiently to ensure safety of the light set and prevent a dangerousburn-out.

However, if it is known that some twinkle light set users prefer foraesthetic reasons to modify the purchased twinkle light set and convertit to an exclusively twinkle bulb light set by replacing each standardbulb of the light set with a twinkle bulb. As a result, when, byhappenstance, all of the illumination circuits of all of the twinklebulbs are open, the current passes substantially unchecked andundiminished through the low resistance bypass circuits in a decidedlyunsafe manner which can lead to melting of conductors, burning ofinsulation, fires, and the like. While twinkle light sets are usuallysold with instructions cautioning against the replacement of standardbulbs with twinkle bulbs, users do not always heed this caution.

Accordingly, recently enacted Underwriters Laboratory (UL) regulations,Section 588, requires that a series-wound twinkle light set have aminimum of fifty bulbs per circuit (to minimize the current passingthrough any given bulb) and that at least twenty-five of such fiftybulbs be standard steady-burning bulbs (as opposed to non-standardtwinkle bulbs). This ensures that in each circuit of a series-woundtwinkle light set there are an adequate number of ordinary bulbs todissipate the current, even if by happenstance all of the twinkle bulbsare passing the current through the low resistance bypass circuitsrather than the high resistance illumination circuits.

Accordingly, it is an object of the present invention to provide atwinkle light set which meets UL standards, and in particular Section588 thereof.

Another object is to provide such a light set which precludes the userfrom replacing standard steady-burning bulbs with non-standard twinklebulbs.

A further object is to provide such a light set which is simple andeconomical to manufacture, use and maintain.

SUMMARY OF THE INVENTION

It has now been found that the above and related objects of the presentinvention are obtained in a twinkle light set comprising, alternatelyfrom one end of a light set to an opposite end of a light set, at leastone standard bulb socket configured and dimensioned to operativelyreceive a standard (e.g., steady-burning) bulb and at least onenon-standard bulb socket configured and dimensioned to operativelyreceive a non-standard twinkle bulb. The standard and non-standard bulbsockets are configured and dimensioned to operatively receive onlystandard and non-standard bulbs, respectively.

In a preferred embodiment, the interior of the standard bulb socket issized differently (preferably smaller) in at least one dimension thanthe interior of the non-standard bulb socket such that the standard bulbsocket cannot operatively receive a non-standard bulb.

The invention also encompasses, in combination, a twinkle bulb lightset, a plurality of standard (e.g. steady-burning) bulbs and a pluralityof non-standard twinkle bulbs. The exterior of the base portion of eachof the non-standard bulbs is sized differently (preferably greater) inat least one dimension than the exterior of the base portion of each ofthe standard bulbs such that the standard bulb socket cannot operativelyreceive a non-standard bulb. Preferably, the non-standard bulb socketdefines a keyway, the non-standard bulb defines a mating key, and thestandard bulb socket lacks a mating keyway, whereby a non-standard bulbwill not fit in a standard bulb socket.

BRIEF DESCRIPTION OF THE DRAWING

The above and related objects, features and advantages of the presentinvention will be more fully understood by reference to the followingdetailed description of the presently preferred, albeit illustrative,embodiments of the present invention when taken in conjunction with theaccompanying drawing wherein:

FIG. 1 is a fragmentary schematic view of a twinkle light set havingsmaller standard bulb sockets and larger non-standard twinkle bulbsockets;

FIG. 2 is a schematic representation of one embodiment of a twinkle bulbin a preferred twinkle bulb socket;

FIG. 3 is a sectional view taken along the line 3—3 of FIG. 2;

FIG. 4 is a schematic representation of another embodiment of a twinklebulb in another preferred twinkle bulb socket; and

FIG. 5 is a sectional view thereof taken along the line 5—5 of FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawing, and in particular to FIG. 1 thereof,therein illustrated is a twinkle light set according to the presentinvention, generally designated by the reference numeral 10. Theillustrated light set 10 is an icicle light set wherein the variousbulbs are disposed on light strings depending from the horizontallyextending active and return wires A, R which connect the two ends of thelight set. While the illustrated light set involves a standard icicle orlight string 12, followed by a twinkle light string 14, followed byanother standard light string 16, followed by another twinkle lightstring 18, clearly different icicle light set patterns may be used; forexample, each standard light string 12, 16 may be replaced by more thanone standard light string and each twinkle light string, 14, 18 may bereplaced by more than one twinkle light string. Thus, a group or stringset of standard bulb light strings 12, 16 may alternate with a group orset of twinkle light strings 14, 18. Indeed, as will be appreciated bythose skilled in the art, the twinkle light set 10 according to thepresent invention need not be in the form of an icicle light set, andmay instead be a net or mesh light set, a patterned light set (forexample, forming diamonds rather than rectangles) or the like. The nodesor connections between adjacent light strings may be formed either atthe lamp sockets or at the wires connecting the lamp sockets of eachlight string.

Each standard or twinkle light string 12-18 is connected to thehorizontally extending active wire A at point 20 and to the horizontallyextending return wire R at point 22. Clearly, the height of each lightstring 12-18, may be varied to incorporate the desired number of bulbsper light string and the number of light strings in a given light setmay be varied to provide a desired number of bulbs in a light set.

In order to preclude the user from modifying the light set 10 afterpurchase so that it is no longer safe and remains in compliance with ULstandards, the light set 10 comprises, alternately from one end 30 ofthe light set 10 to an opposite end 32 of the light set 10, at least onestandard bulb socket 50 and at least one non-standard bulb socket 52.The standard bulb socket 50 is configured and dimensioned to operativelyreceive the base portion of a standard steady-burning bulb 51, while thenon-standard bulb socket 52 is configured and dimensioned to operativelyreceive the base portion of a non-standard twinkle bulb 53. Moreparticularly, the standard and non-standard bulb sockets 50, 52 areconfigured and dimensioned to operatively receive the base portions ofonly standard and non-standard bulbs 51, 53, respectively.

The last requirement may be achieved through a variety of differentmechanisms. Preferably the interior of the standard bulb socket 50 issized differently (as illustrated, smaller) than the interior of thenon-standard bulb socket 52 such that the standard bulb socket 50 cannotoperatively receive therein a non-standard bulb 53. Alternatively, theinteriors of each of the standard bulb sockets 50 may be greater thanthe exterior of each of the non-standard bulbs 53. Thus, as illustratedin FIGS. 2 and 3, a twinkle light set 10 may be used with a plurality ofstandard steady-burning bulbs 51 and a plurality of non-standard twinklebulbs 53 wherein each of the non-standard bulbs 53 has at least oneexterior dimension sized differently (as illustrated, greater) than thatof each of the standard bulbs 51, so as to preclude operative receipt ofa non-standard bulb 53 in the interior of a standard bulb socket 50.Alternatively, as illustrated in FIGS. 4 and 5, each of the non-standardbulbs 53 may have at least one exterior dimension smaller than that ofeach of the standard bulbs 51 so that the twinkle bulb socket 52 cannotoperatively receive therein a standard bulb 51.

For example, as illustrated in FIGS. 2 and 3, the non-standard bulbsocket 52 may define an interior surface having an outwardly projectingkeyway 60 and the non-standard bulb 53 may define an exterior surfacehaving an outwardly projecting mating key 62 such that the key 62 of thenon-standard bulb 53 precludes operative receipt thereof in a standardbulb socket 50 lacking a corresponding keyway 60. Alternatively, asillustrated in FIGS. 4 and 5, the non-standard bulb socket 52 may definean interior surface having an inwardly projecting key 64 and thenon-standard bulb 53 may define an exterior surface having an inwardlyprojecting mating keyway 66 such that the key 64 of the non-standardbulb socket 52 allows operative receipt of a non-standard bulb 53therein, yet precludes operative receipt therein of a standard bulb 51lacking the keyway 66 to receive the socket key 64. The object of suchdesigns is to preclude the introduction of a non-standard bulb 53 into astandard bulb socket 50, for the sake of safety and to meet ULstandards. The designs may or may not permit the introduction of astandard bulb 51 into a non-standard bulb socket 52, as such asubstitution does not involve safety considerations or violate ULstandards.

Preferably the standard bulb socket interior is smaller in at least onedimension than the non-standard bulb socket interior, and thenon-standard bulb exterior is greater in such at least one dimensionthan the standard bulb exterior. Preferably, the non-standard bulbsocket 52 defines a keyway 60, the non-standard bulb 53 defines a matingkey 62, and the standard bulb socket 50 lacks a mating keyway, whereby anon-standard bulb 53 will not fit in a standard bulb socket 50.

It is a matter of choice whether or not the exteriors of the differenttypes of bulb sockets—that is, the standard bulb socket 50 and thenon-standard bulb socket 52—are identical in configuration anddimensions (or even color) so long as the user cannot inadvertently orintentionally substitute a non-standard twinkle bulb 53 within anordinary or standard light socket 50. However, if desired, some clearlyvisible distinction (such as color or other indicia) may be used tosignify to the user that a particular bulb socket is a non-standard bulbsocket 52.

While the principles of the present invention have been explained abovein terms of a standard steady-burning bulb and a non-standard twinklebulb, it is irrelevant for the purposes of the present invention whetherthe standard bulb 51 is a steady-burning bulb or a flasher bulb.

Clearly, the non-standard bulb 53 may fit into the standard bulb socket50 as long as it is not “operatively” received therein—i.e., does notestablish effective electrical communication therewith.

To summarize, the present invention provides a twinkle light set whichmeets UL standards, and in particular Section 588 thereof, by precludingthe user from replacing standard steady-burning bulbs with non-standardtwinkle bulbs. The light set is simple and economical to manufacture,use and maintain.

Now that the preferred embodiments of the present invention have beenshown and described in detail, various modifications and improvementsthereon will become readily apparent to those skilled in the art.Accordingly, the spirit and scope of the present invention is to beconstrued broadly and limited only by the appended claims and not by theforegoing specification.

1. A twinkle light set comprising: alternately from one end of said light set to an opposite end of said light set, at least one standard bulb socket electrically operatively receive receiving a standard bulb, whether a conventional steady burning or a conventional flashing bulb, and at least one non-standard bulb socket electrically operatively receiving a non-standard twinkle bulb; said standard and non-standard bulb sockets being configured and dimensioned to electrically operatively receive only standard and non-standard bulbs, respectively; said standard bulb socket being configured and dimensioned not to electrically operatively receive a non-standard bulb because of interference of a laterally larger exterior dimension of the non-standard bulb with a laterally smaller interior dimension of said standard bulb socket, notwithstanding the use of excessive manual force to attempt to overcome such interference.
 2. The light set of claim 1 wherein the interior of said standard bulb socket is sized differently in at least one dimension than the interior of said non-standard bulb socket such that said standard bulb socket cannot electrically operatively receive a non-standard bulb.
 3. The light set of claim 2 wherein said standard bulb socket interior is smaller in said at least one dimension than said non-standard bulb socket interior.
 4. In combination, a twinkle light set of claim 1, a plurality of standard bulbs and a plurality of non-standard twinkle bulbs, the exterior of each of said non-standard bulbs is sized differently in at least one dimension than the exterior of each of said standard bulbs such that said standard bulb socket cannot electrically operatively receive a non-standard bulb.
 5. The combination of claim 4 wherein said non-standard bulb is greater in said at least one dimension than said standard bulb.
 6. In combination, a twinkle light set, a plurality of standard bulbs and a plurality of non-standard twinkle bulbs, said twinkle light set comprising: alternately from one end of said light set to an opposite end of said light set, at least one standard bulb whether a conventional steady burning or a conventional flashing bulb socket electrically operatively receiving a standard bulb, whether a conventional steady burning or a conventional flashing bulb, and at least one non-standard bulb socket electrically operatively receive receiving a non-standard twinkle bulb; said standard and non-standard bulb sockets being configured and dimensioned to electrically operatively receive only standard and non-standard bulbs, respectively; the interior of said standard bulb socket being sized differently in at least one dimension than the interior of said non-standard bulb socket such that said standard bulb socket cannot electrically operatively receive a non-standard bulb; and the exterior of each of said non-standard bulbs being sized differently in at least one dimension than the exterior of each of said standard bulbs such that said standard bulb socket cannot electrically operatively receive a non-standard bulb due to interference, notwithstanding the use of excessive manual force to attempt to overcome such interference.
 7. The combination of claim 6 wherein said standard bulb socket interior is smaller in said at least one dimension than said non-standard bulb socket interior, and said non-standard bulb is greater in said at least one dimension than said standard bulb.
 8. The combination of claim 6 wherein the non-standard bulb socket defines a keyway, the non-standard bulb defines a mating key, and the standard bulb socket lacks a mating keyway, whereby a non-standard bulb will not electrically operatively fit in a standard bulb socket.
 9. A twinkle light set comprising: alternately from one end of said light set to an opposite end of said light set at least one standard bulb socket electrically operatively receiving a standard bulb whether a conventional steady burning or a conventional flashing bulb, and at least one non-standard bulb socket electrically operatively receiving a non-standard twinkle bulb; only said non-standard bulb sockets being configured and dimensioned to electrically operatively receive non-standard bulbs; said standard bulb socket being configured and dimensioned not to electrically operatively receive a non-standard bulb because of interference of a laterally larger exterior dimension of the non-standard bulb with a laterally smaller interior dimension of said standard bulb socket, notwithstanding the use of excessive manual force to attempt to overcome such interference.
 10. The light set of claim 9 wherein the interior of said standard bulb socket is sized differently in at least one dimension than the interior of said non-standard bulb socket such that said standard bulb socket cannot electrically operatively receive a non-standard bulb.
 11. The light set of claim 10, wherein said standard bulb socket interior is smaller in said at least one dimension than said non-standard bulb socket interior.
 12. In combination, a twinkle light set of claim 9, a plurality of standard bulbs and a plurality of non-standard twinkle bulbs, the exterior of each of said non-standard bulbs being sized differently in at least one dimension than the exterior of each of said standard bulbs such that said standard bulb socket cannot electrically operatively receive a non-standard bulb.
 13. The combination of claim 12 wherein said non-standard bulb is greater in said at least one dimension than said standard bulb.
 14. In combination, a twinkle light set, a plurality of standard bulbs and a plurality of non-standard twinkle bulbs, said twinkle light set comprising: alternately from one end of said light set to an opposite end of said light set, at least one standard bulb socket electrically operatively receiving a standard bulb whether a conventional steady burning or a conventional flashing bulb, and at least one non-standard bulb socket electrically operatively receiving a non-standard twinkle bulb; only said non-standard bulb sockets being configured and dimensioned to operatively receive non-standard bulbs; the interior of said standard bulb socket being sized differently in at least one dimension than the interior of said non-standard bulb socket such that said standard bulb socket cannot electrically operatively receive a non-standard bulb; and the exterior of each of said non-standard bulbs being sized differently in at least one dimension than the exterior of each of said standard bulbs such that said standard bulb socket cannot electrically operatively receive a non-standard bulb due to interference, notwithstanding the use of excessive manual force to attempt to overcome such interference.
 15. The combination of claim 14 wherein said standard bulb socket interior is smaller in said at least one dimension than said non-standard bulb socket interior, and said non-standard bulb is greater in said at least one dimension than said standard bulb.
 16. The combination of claim 14 wherein the non-standard bulb socket defines a keyway, the non-standard bulb defines a mating key, and the standard bulb socket lacks a mating keyway, whereby a non-standard bulb will not electrically operatively fit in a standard bulb socket. 